The invention relates to a device for active vibration damping of an object, with a vibration sensor, a control circuit and an actuator.
Such devices are also known as "active damping systems" in robot technology; there, the vibration of the free end of a beam is damped, and the beam is mounted at its other end in a rotary joint and is to be brought by a drive to a desired angular position relative to this joint. Apart from the control of this drive by various sensor arrangements, a sensor and an actuator are also united at the free end of the beam. Controllable electromagnetic linear drives with moved inert masses are known, for example, as actuators. This is described, for example, in H. B. Kuntze, Position Control of Industrial Robots-Impacts, Concepts and Results, Symposium Robot Control, October 5-7, Karlsruhe, in particular FIG. 9.
Accuracy, speed and the accessible measurement region of measurements are increasingly common requirements in precision measuring machines. To increase accuracy, vibrations have to be suppressed, generally requiring rigid structures with large masses. However, rigid structures with large masses hinder rapid travel. A larger measurement region necessitates large structural lengths and travel paths, so that the greatest possible accelerations and travel speeds are striven for, thus accentuating the requirements for vibrational rigidity and light construction. A critical component here is the spindle, which has to be accelerated in each direction, and the free length of which must greatly change in order to achieve a large measurement region. Its bending vibrations are hence considerable, but the variable lengths are however prejudicial to the use of conventional damping means.
An objection to the arrangement of an active damping system with united arrangement of sensor and actuator is that the device then disturbs the spindle end with not inconsiderable mass and constructional size. The action of the actuator is, in addition, then dependent or the free length of the spindle.